# Copyright (c) Meta Platforms, Inc. and affiliates.
# All rights reserved.
#
# This source code is licensed under the terms described in the LICENSE file in
# the root directory of this source tree.

from enum import StrEnum
from typing import Any, Literal, Protocol, runtime_checkable

from pydantic import BaseModel, ConfigDict, Field, field_validator

from llama_stack_api.resource import Resource, ResourceType
from llama_stack_api.schema_utils import json_schema_type, webmethod
from llama_stack_api.version import LLAMA_STACK_API_V1


class CommonModelFields(BaseModel):
    metadata: dict[str, Any] = Field(
        default_factory=dict,
        description="Any additional metadata for this model",
    )


@json_schema_type
class ModelType(StrEnum):
    """Enumeration of supported model types in Llama Stack.
    :cvar llm: Large language model for text generation and completion
    :cvar embedding: Embedding model for converting text to vector representations
    :cvar rerank: Reranking model for reordering documents based on their relevance to a query
    """

    llm = "llm"
    embedding = "embedding"
    rerank = "rerank"


@json_schema_type
class Model(CommonModelFields, Resource):
    """A model resource representing an AI model registered in Llama Stack.

    :param type: The resource type, always 'model' for model resources
    :param model_type: The type of model (LLM or embedding model)
    :param metadata: Any additional metadata for this model
    :param identifier: Unique identifier for this resource in llama stack
    :param provider_resource_id: Unique identifier for this resource in the provider
    :param provider_id: ID of the provider that owns this resource
    """

    type: Literal[ResourceType.model] = ResourceType.model

    @property
    def model_id(self) -> str:
        return self.identifier

    @property
    def provider_model_id(self) -> str:
        assert self.provider_resource_id is not None, "Provider resource ID must be set"
        return self.provider_resource_id

    model_config = ConfigDict(protected_namespaces=())

    model_type: ModelType = Field(default=ModelType.llm)

    @field_validator("provider_resource_id")
    @classmethod
    def validate_provider_resource_id(cls, v):
        if v is None:
            raise ValueError("provider_resource_id cannot be None")
        return v


class ModelInput(CommonModelFields):
    model_id: str
    provider_id: str | None = None
    provider_model_id: str | None = None
    model_type: ModelType | None = ModelType.llm
    model_config = ConfigDict(protected_namespaces=())


class ListModelsResponse(BaseModel):
    data: list[Model]


@json_schema_type
class OpenAIModel(BaseModel):
    """A model from OpenAI.

    :id: The ID of the model
    :object: The object type, which will be "model"
    :created: The Unix timestamp in seconds when the model was created
    :owned_by: The owner of the model
    :custom_metadata: Llama Stack-specific metadata including model_type, provider info, and additional metadata
    """

    id: str
    object: Literal["model"] = "model"
    created: int
    owned_by: str
    custom_metadata: dict[str, Any] | None = None


@json_schema_type
class OpenAIListModelsResponse(BaseModel):
    data: list[OpenAIModel]


@runtime_checkable
class Models(Protocol):
    async def list_models(self) -> ListModelsResponse:
        """List all models.

        :returns: A ListModelsResponse.
        """
        ...

    @webmethod(route="/models", method="GET", level=LLAMA_STACK_API_V1)
    async def openai_list_models(self) -> OpenAIListModelsResponse:
        """List models using the OpenAI API.

        :returns: A OpenAIListModelsResponse.
        """
        ...

    @webmethod(route="/models/{model_id:path}", method="GET", level=LLAMA_STACK_API_V1)
    async def get_model(
        self,
        model_id: str,
    ) -> Model:
        """Get model.

        Get a model by its identifier.

        :param model_id: The identifier of the model to get.
        :returns: A Model.
        """
        ...

    @webmethod(route="/models", method="POST", level=LLAMA_STACK_API_V1, deprecated=True)
    async def register_model(
        self,
        model_id: str,
        provider_model_id: str | None = None,
        provider_id: str | None = None,
        metadata: dict[str, Any] | None = None,
        model_type: ModelType | None = None,
    ) -> Model:
        """Register model.

        Register a model.

        :param model_id: The identifier of the model to register.
        :param provider_model_id: The identifier of the model in the provider.
        :param provider_id: The identifier of the provider.
        :param metadata: Any additional metadata for this model.
        :param model_type: The type of model to register.
        :returns: A Model.
        """
        ...

    @webmethod(route="/models/{model_id:path}", method="DELETE", level=LLAMA_STACK_API_V1, deprecated=True)
    async def unregister_model(
        self,
        model_id: str,
    ) -> None:
        """Unregister model.

        Unregister a model.

        :param model_id: The identifier of the model to unregister.
        """
        ...
